Leonard paget



UNITED STATES PATENT OFFICE.

LEONARD PAGET, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO CHARLES J. KINTN ER, OF SAME PLACE.

GAS-INCAND ESCENT.

srEoIFIoATIoN forming part of'Letters Patent N. 4o1,s99, dated April 23, 1889.

Application filed March 30, 1889. Serial No. 305,437. (No specimens.)

. tion.

My invention relates particularly to that type of incandescents in which a non-friable base or. support is coated with the incandescent material, and its object is to devise an incandescent which shall have great durability. I 4

To this end my. invention consists in 'the novel process hereinafter described and particularly claimed. I

In the prior state of the art it was old to coat with an earthy incandescing substance like magnesiaa non-friable base orsupport such as a platinum wire-by causing the incandescing substance to adhere to the exterior surface of such base or support in several ways which are well known, and therefore need not be described here; but in'all'of the processes familiar to me by which the incandescing material is coated upon a base or support there is not an absolute integrality of connection between the two, by which I mean that the incandescing material does not penetrate or'is not absorbed into the pores of the non-friable base or support.

In my improved incandescent there is absolute integrality of connection between the two, as I will now proceed to describe.

I take a'metallic wire, preferably of steel or platinum, or any metal in which there is little or no carbon, although fair results may be had with some grades of iron wire, and I form this Wire into an incandescent hood or mantle of the. desired configuration or shape, either by weaving or in any preferred manner, and I then make a solution, preferably alcoholic, of

' some earthy material-as, for instance, an

alcoholic solution of chloride of magnesium, it being preferably a saturated solution. I then connect the ends of the incandescent or hood to an electrical generator by any preferred means, said generator having sufficient current capacity to heat the entire incandescent to a dull-red temperature in air when in operation. To avoid danger of an explosion,

however, care should be taken to entirely im- I merse the incandescent thus connected in the electrical circuit in the solution, if of alcohol, before the current is closed and the generator is operatively connected. Of course any generator of electricity giving the necessary current tension and supply maybe used. When themetallic' hood or incandescent becomes thus heated to the desired temperature, Ihave discovered that its surface pores expand or enlarge very materially. The heat generated by the electrical current, besides expanding the pores of the support, volatilizes the solution and causes the magnesia ortoxide of magnesium held in solution to be absorbed into said pores. This process is continued until a coating of the desired thickness of the magnesia.(or magnesium oxide) attaches itself to those p'articlesgwhich have been already absorbed and to the surface of the wire itself. The hood or incandescent is now removed from the bath and is ready for use. I have obtained excellent resultsfrom an incan descent prepared by this process upon a platinum wire, which after the process failed to disclose to the naked eye any coating of magnesia or magnesium oxide, thus showing that the incandescing material or magnesia was absorbed into the pores of the wire.

The hood or incandescent may, if desired, be heated before immersion, and by other means than electrical, and then dipped into the solution, continuing the heating and dipthe incandescing material, thereby giving innitrate of magnesium, nitrate of aluminium, and chloride of zirconium.

I am aware of a patent granted to Alexander'Bernstein by the United States on the 30th of August, 1SS7,N0. 369,091, for an improved process of coating electric incandescent filaments made of carbon with magnesium oxide. It is well known in the art of electrical illumination that carbon and analogous conducting filaments which decrease in their elec trical resistance on heating to incandescence are used in preference to metal conductors, which increase their resistance under like conditions, thereby wasting electrical energy. I have discovered that this increase in the resistance of a metallic conductor is due to the increased porosity of the metal. under heat, and that in carbon and analogous incandescent electric-light conductors there is decreased porosity, and have taken advantage of this discovery to cause the pores of a metal conductor to absorb an incandescing substance, as above described, and in this re spect my process differs from that of Bernstein. It is also afact that a carbon or analogous conductor of the type just mentioned would be destructible under the oxidizing influence of a gas-flame.

I am also aware that it is old to dissolve an oxide in an acid and then coat a wire with this solution and finally subject the wire thus coated to heat, as described in English patent to Edison, No. 5,306 of 1878; but this process is the reverse of mine, and cannot act to cause the oxide to penetrate the pores, as does my process, and therefore does not produce my improved incandescent.

I make no claim here to the process de scribed, as this subject-matter is claimed by me in another application filed of even date herewith, Serial No. 305,436.

I make no claim to an incandescent of the type named, in which the incandescing material is held to a base or support otherwise than in an integral sense. By the word or expression integral, as herein used, I mean that the incandescing material penetrates or is absorbed into the pores of the non-friable base or support.

lVhat I do claim, and desire to secure by Letters Patent of the United States, is

1. As a new article of manufacture, an incandescent consisting of a non-friable base or support having an incandescing substance embedded in its pores, whereby integrality of connection exists between the base or support and the incandescing substance, substantially as described.

2. As a new article of manufacture, an incandescent consisting of a non-friable base or support holding an incandescing substance in its surface pores and an exterior coating of said incandescing material attached to the embedded material and to the surface of the base or support, substantially as described.

3. As a new article of manufacture, an incandescent consisting of a metallic base or support having a coating of an incandescing material which penetrates the surface-pores of the base or support, substantially as described.

at. As a new article of manufacture, an incandescent consisting of a metallic base or support having a coating of an incandescing material of highly-refractory nature, which penetrates the surface pores of the base or support and forms also a coating about the exterior surface, the two being thus integrally united, substantially as described.

5. As a new article of manufacture, an incandescent consisting of a metallic wire base or support coated with an incandescing material which penetrates the surface pores of the wire and thus becomes integrally attached to said base or support, substantially as described.

6. As a new article of manufacture, an incandescent consisting of a non-friable base or support having magnesium oxide embedded in its surface pores, substantially as described.

7. As a new article of manufacture, an incandescent consisting of a non-friable base or support having magnesium oxide embedded in its surface pores and also a coating of said oxide on the surface of said base or support, substantially as described.

8. As a new article of manufacture, an incandescent consisting of a metallic base or support having magnesium oxide embedded in its surface pores and covering also the entire surface of the base or support, substantially as described.

LEONARD PAGET.

lVitnesses: I

A. E. MCKEGHNIE, L. V. HARWOOD. 

